MythxEngine MCP server

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• add_combat_condition

  Add a condition to a combatant. Supports advantage/disadvantage and resistance/vulnerability effects.

• add_deadline

  Add a deadline/countdown to track. Specify either expiresIn (minutes from now) or expiresAt (specific time).

• add_note

  Add a timestamped note to the session

• add_npc

  Register a fabricated NPC on the session. Returns a stable `npcId` to use in `generate_portrait` and `showDialogue`. Use BEFORE introducing any NPC that isn't already in the world pack \u2014 without this the NPC has no identity and their portrait can't be tracked across turns.

• advance_time

  Advances time by N minutes

• advance_turn

  Move to the next player in turn order

• apply_condition

  Add a condition to a character (narrative/exploration). For combat, use `add_combat_condition` instead so combat effects (advantage/disadvantage, modifiers) are picked up.

• apply_damage

  Apply damage directly to a combatant (bypassing attack roll)

• assemble_world_pack

  Combine all generated content into a complete WorldContentPack and save it.

• assign_character

  Link a player to a character

• attack

  Perform an attack against a target. Supports advantage/disadvantage and damage type for resistance/vulnerability. Returns an envelope with `outcome` (five-tier) and a one-line `summary` as the headline; mechanical detail is in `result`, follow-up moves in `suggested_next`.

• batch_generate

  After seeding, returns ALL generation prompts at once for parallel LLM execution. Execute each prompt with an LLM, then call save_generation_result for each result. This replaces calling individual generate_* tools one by one.

• check_clock_triggers

  Check if any time-based clock stages have triggered based on current game time.

• create_characterwrite action

  Create a new character in the session

• create_playerwrite action

  Add a player (human or AI) to the session

• create_sessionwrite action

  Create a new game session, optionally associated with a world pack.

• damage_character

  Deal damage to a character (narrative/environmental, not from combat resolution). Floors HP at 0 and reports defeat. For combat attacks, use `attack`. For combat-target damage, use `apply_damage`.

• delete_characterwrite action

  Delete a character from the session

• delete_playerwrite action

  Remove a player from the session

• delete_sessionwrite action

  Delete a session and all its data

• end_combat

  End the current combat

• end_turns

  End turn-based coordination and return to free-form play

• generate_archetypes

  Generate playable character archetypes based on the world seed. Returns a prompt for LLM execution.

• generate_arcs

  Generate story arcs that group situations around central tensions. Returns a prompt for LLM execution.

• generate_conditions

  Generate status effects and conditions based on the world seed. Returns a prompt for LLM execution.

• generate_encounters

  Generate encounters based on the world seed. Returns a prompt for LLM execution.

• generate_factions

  Generate factions with relationships, resources, and territory based on the world seed. Returns a prompt for LLM execution.

• generate_items

  Generate items based on the world seed. Returns a prompt for LLM execution.

• generate_locations

  Generate locations based on the world seed. Returns a prompt for LLM execution.

• generate_monsters

  Generate monsters based on the world seed. Returns a prompt for LLM execution.

• generate_narrative

  Generate narrative guidance (opening scenes, plot hooks, conflicts) based on the world seed. Returns a prompt for LLM execution.

• generate_npcs

  Generate NPCs based on the world seed. Returns a prompt for LLM execution.

• generate_situations

  Generate situations (nodes) based on the world seed using Alexandrian node-based design. Returns a prompt for LLM execution. Can generate all at once or one at a time using count=1 with focusOn for better parallelism.

• generate_world_images

  Generate images for world pack entities (all entity types by default). Run after assemble_world_pack to pre-bake character select images.

• generate_world_seedwrite action

  Create the foundation for a new world from a campaign seed prompt. Returns a prompt for LLM execution.

• get_active_clocks

  List all active situation clocks with their current status.

• get_ai_player_context

  Get full context for an AI player to make a decision

• get_arc

  Get full details for a specific story arc from a world pack. Includes structure, situations, and resolution patterns.

• get_archetype

  Get full details for a specific archetype from a world pack.

• get_available_leads

  List leads that are currently available for discovery. Filter by location, NPC, or prominence.

• get_character

  Get a character's full details

• get_combat_state

  Get the current combat state

• get_condition

  Get full details for a specific condition from a world pack.

• get_current_turn

  Get the current turn state and active player

• get_discovered_leads

  List all leads that players have discovered.

• get_encounter

  Get full details for a specific encounter from a world pack.

• get_faction

  Get full details for a specific faction from a world pack.

• get_generation_status

  Check world generation progress. Shows completed, in-progress, and pending phases with entity counts.

• get_item

  Get full details for a specific item from a world pack.

• get_location

  Get full details for a specific location from a world pack.

• get_monster

  Get full details for a specific monster from a world pack.

• get_npc

  Get full details for a specific NPC from a world pack.

• get_npc_disposition

  Quick check: How does this NPC feel about the party?

• get_player

  Get a player's full details

• get_relationship

  Get an NPC's current attitude and interaction history with the party.

• get_situation

  Get full details for a specific situation from a world pack. Includes leads, clock, complications, and outcomes.

• get_stress

  Get a character's current stress level, trauma status, and whether they can safely push.

• get_time

  Returns current game time for session

• heal_character

  Restore HP to a character. Capped at max HP. Use for any HP recovery (rest, spell, potion narration, GM fiat).

• initialize_relationship

  Start tracking a relationship with an NPC.

• list_characters

  List all characters in a session

• list_players

  List all players in a session

• list_relationships

  List all tracked NPC relationships.

• list_sessions

  List all game sessions. Optionally filter by world pack ID.

• list_world_packs

  List all saved world packs with their metadata and content counts.

• load_session

  Load an existing game session by ID. Returns session state summary.

• load_skill

  Load on-demand skill guidance into your context. Use when the current situation matches a skill's purpose (e.g. about to generate images, entering combat). The skill body is markdown \u2014 read it and apply it on this turn. Skill names come from the "Available skills" section of your system prompt. Available skills: …

• load_world_summary

  Load a compact GM reference for a world pack. Returns a token-efficient summary with entity IDs, names, and key stats. Use get_* tools for full entity details.

• next_turn

  Advance to the next turn in combat

• pause_clock

  Pause an active clock. Time-based triggers will not fire while paused.

• push_roll

  Spend 2 stress to add +1d6 bonus to a failed or partial roll. Can trigger trauma if stress exceeds max. Returns an envelope with `outcome` ('pushed' or 'trauma_gained') and a one-line `summary` as the headline; mechanical detail is in `result` (including `previousOutcome` \u2192 `newOutcome`, the re-derived outcome tier for the pushed margin), stress/trauma changes in `state_delta`.

• recover_stress

  Recover stress during rest. Short rest recovers 2 stress, long rest recovers all stress.

• remove_conditionwrite action

  Remove a condition from a character. Accepts the condition id OR its display name (case-insensitive). No-op if the condition isn't on the character.

• remove_deadlinewrite action

  Remove a deadline by ID

• request_player_input

  Mark a human player as awaiting input for their turn

• resist_consequence

  Spend stress to reduce a consequence. Roll ability to potentially reduce cost. Minor=1, Moderate=2, Severe=3 base cost. Pass `damage` when the consequence is HP damage \u2014 the tool then applies the mechanical effect itself (successful resist halves it, failed resist lands in full; set `alreadyApplied` if the damage already hit HP so it refunds the reduction). Returns an envelope with `outcome`

• resume_clock

  Resume a paused clock.

• resume_generation

  Resume an interrupted world generation session. Analyzes session state to report progress and optionally reset incomplete steps.

• reveal_clock

  Make a hidden situation clock visible to players on their HUD. Call this exactly when your narration reveals the threat or deadline to the players \u2014 not before. Until revealed, clocks are GM-only state and may tick in secret.

• reveal_lead

  Mark a lead as discovered by the players.

• roll_custom_test

  Perform a custom test defined in the world pack rules (e.g., panic check, sanity roll). Returns success/failure, any table rolls, and effects to apply.

• roll_dice

  Roll dice using standard notation (e.g., '2d6+3', 'd20', '4d6'). Optionally use session RNG for determinism.

• roll_initiative

  Roll initiative for all combatants and set turn order

• roll_test

  Perform a skill or ability test for a character. Rolls d20 + ability + skill + modifiers vs difficulty. Supports advantage/disadvantage. Returns an envelope with `outcome` (five-tier) and a one-line `summary` as the headline; mechanical detail is in `result`, follow-up moves in `suggested_next`.

• save_generation_result

  Save LLM-generated content back to the session. Call this after executing a generation prompt. Accepts JSON or XML formatted results.

• search_leads

  Search for leads by keyword across all lead information.

• search_notes

  Search session notes by keyword or tags

• set_play_mode

  Set the play mode for a session. 'interactive' prompts the player for decisions, 'auto' plays all characters autonomously. Persists across context compaction.

• set_time

  Sets game time (for initialization/GM override)

• start_combat

  Initialize combat with characters and enemies. Returns an envelope with `outcome: 'combat_started'` and a one-line `summary` as the headline; combatant lists in `result`, combat state in `state_delta`. Always follow with `roll_initiative` (also surfaced in `suggested_next.next_action`).

• start_situation_clock

  Start a situation clock. The clock tracks what happens if PCs don't intervene.

• start_turns

  Begin turn-based coordination for multi-player gameplay

• submit_ai_player_actionwrite action

  Record an AI player's decided action

• submit_player_actionwrite action

  Record a human player's chosen action

• suggest_lead_opportunity

  Suggest ways to naturally surface leads pointing to a target situation. Supports the Three Clue Rule.

• tick_clock

  Manually advance a clock to its next stage. Use for event-based triggers or GM override.

• update_companion_statewrite action

  Update an AI companion's internal state (loyalty, mood, grievances, memories). Call after events that would plausibly affect the companion's attitude toward the party.

• update_pacing_statewrite action

  Update narrative pacing state after each beat. Track tension level, phase transitions, and spotlight rotation to maintain balanced storytelling.

• update_playerwrite action

  Update a player's status, name, controlType, or AI persona

• update_relationshipwrite action

  Record an interaction and update NPC relationship. Automatically adjusts attitude based on impact.

• Code scan6 source files scanned25/25
• –Live reliabilityno gateway calls yet and no remote to proben/a
• –Tool poisoningtools not inspected (local package is not executed); not countedn/a
• Auth qualitylocal package, no credentials required12/15
• Maintenancelast push 37 days ago12/15
• Maintainer identityregistry namespace matches repository owner7/10

Safety score

86/100

higher than 72% of 48,255 servers

Tools

100

the typical server has 7

Tools that change things

15%

typical: 0%. Fewer write tools means less an agent can break

GitHub stars

2

more than 75% of 28,688 servers

Downloads a week

223

more than 77% of 12,191 servers with a package

MythxEngine: common questions

Is MythxEngine MCP server safe?

Yes, by our scan: it is graded A (86/100). Read the MythxEngine safety report

How do I install MythxEngine?

It runs on your machine. Copy the Claude Code, Cursor, VS Code or Claude Desktop config from the install section.

Does MythxEngine need an API key?

No secret keys are declared. It reads 1 setting from the environment.

Is MythxEngine maintained?

The last commit was 76 days ago (2026-08-20). The latest release is v0.3.0.

How does MythxEngine compare with other MCP servers?

safety score 86/100 (higher than 72% of 48,255 servers); tools 100 (the typical server has 7); tools that change things 15% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.